Analysis of Fall Transition Season (Sept-Early Dec) Why has the weather been so violent?

Save this PDF as:

Size: px
Start display at page:

Download "Analysis of Fall Transition Season (Sept-Early Dec) Why has the weather been so violent?"

Transcription

1 WEATHER TOPICS Analysis of Fall Transition Season (Sept-Early Dec) 2009 Why has the weather been so violent? As can be seen by the following forecast map, the Fall Transition and early Winter Season of 2009 has been particularly heavy in the North Pacific, with several very deep low pressure systems, long fetches of over 1,000nm with very strong winds, and extremely wide areas of over 6m seas/swells. Reasons for such violent weather are related to several features, including the El Niño phenomenon, sea surface temperatures, global circulation patterns and slightly higher than average tropical cyclone activity in the Northwest Pacific, many of which recurved into the subtropics, bringing warm, moist air which helps fuel explosive development of low pressure systems. For a detailed scientific analysis of the mechanisms involved, please see the following pages.

2 Introduction The Fall Transition Season of 2009 has been particularly heavy in the North Pacific the period September through early December has boasted ten low pressure systems deeper that 970mb, four of which showed central pressures less than 955mb (Figure 1). The presence of a moderate El Niño over the past several months (Figure 2), and its effect on Tropical Storm development, sea surface temperatures and global circulation patterns can be traced as the reason for this particularly heavy weather. El Niño El Niño is part of the climate phenomenon called ENSO El Niño/ Southern Oscillation - which is a periodic change in the atmosphere and ocean of the tropical Pacific. It is defined in the atmosphere by the sign of the pressure difference between Tahiti and Darwin, Australia, and in the ocean by warming or cooling of surface waters of the tropical central and eastern Pacific Ocean. The warm phase of ENSO is known as El Niño, and the cold phase of ENSO is known as La Niña (Figure 3). ENSO events (warm or cool) do not occur with a specific period, and tend to occur every three to eight years. The effects of ENSO are felt globally, but are felt most acutely in the Pacific Ocean, as sea surface temperature anomalies associated with ENSO can affect the circulation patterns of the basin. During El Niño events, the atmospheric pattern is characterized by an eastward extension of the East Asian jest stream from the International Date Line to the southwestern United States, and shifting of that jet stream further south through the mid-latitudes. This results in an amplified main low track and enhanced Aleutian low (Figure 4), meaning that lows within the main low track tend to be stronger, and track further south through the basin. Tropical Storms and Sea Surface Temperatures The transition season of 2009 has seen 15 tropical systems (tropical storm strength and higher), which is near the average of about 13 storms of TS strength or higher for the period September-November (Table 1). Recent research by the Weathernews Voyage Planning team indicates that El Niño typically does not have an effect on the total number of tropical systems average number of storms remains consistent between El Niño, Neutral and La Niña years. However, there are on average 2 more typhoons per year in El Niño years than in neutral or La Niña years. His research shows that tropical cyclones form farther south and east during El Niño event than in neutral or La Niña years (Figure 5). Forming farther south, these cyclones tend to track westward in warmer waters for longer periods of time, allowing tropical depressions to reach tropical storm strength and typhoon strength farther south and east in the basin. Per Lance s research, tropical cyclones tend reach higher maximum wind intensities during El Niño

3 years (on average knots higher than in neutral or La Niña years), and they tend to recurve slightly more often than in ENSO Neutral years and much more often than during La Niña years. The Fall transition season of 2009 (September early December) has seen 19 tropical systems develop, 15 of which were tropical storm strength or higher. Of those 15 systems, 7 recurved through the western ocean into the mid-latitudes of the West or Central Pacific. Four of those recurving systems (Choi-wan, Melor, Lupit and Nida) were significant Typhoons, with maximum wind speeds of 105 kt and higher recorded during their lifetimes. The seven recurving tropical systems (as well as several tropical depressions that also recurved) during this period brought rich tropical moisture in the mid-latitudes, which helped prime the atmosphere for more violent weather during this transition season in two ways. Firstly, recurving tropical systems bring warm, humid air to the mid latitudes. When that warm, humid air converges with cold air associated with mid-latitude systems, the warm, humid air can serve as fuel for the mid-latitude systems by providing additional latent heat energy. This allows the mid-latitude storms to deepen further, sometimes very quickly, resulting in intense storms with very heavy associated conditions. Such was the case with Typhoons Choi-wan (in Mid-September), Lupit (in late October) and Nida (in early December), each of which deepened to lows with central pressure of 967mb or lower after extratropical transition or combining with mid-latitude low. Secondly, strong recurving tropical systems (as in the case with the four systems mentioned above) typically have strong southerly winds along the eastern side of the system. These strong winds can serve to push warm surface waters northward from the tropics into the mid-latitudes. Figure 6 shows a positive sea surface temperature (SST) anomaly was present across much of the West Pacific, west of the Dateline for the period September 1- December 7. This figure shows a significantly positive anomaly between 160E-170E, 35N-40N. Positive sea surface temperature anomalies were also present east of the dateline, south of 40N. The strong anomaly in the Western Pacific can be attributed to strong recurving tropical systems pushing warm SSTs north into the mid-latitudes, effectively warming the average SST in the West Pacific by almost 2.5C in some areas. The presence of this pool of warm water served as additional fuel for developing lows in the Western Pacific. The main cyclogenesis area of the Pacific basin is off the coast of Japan, associated with the Kuroshio current core. With warmer water present over a much larger area than normal, lows that developed off the coast of Japan stayed over these warmer waters for longer, allowing them to gain more energy than they would normally. When those lows converged with cold air as they tracked northeastward into the Bering Sea or Gulf of Alaska, this additional energy allowed lows to deepen further and more quickly than if a typical sea surface temperature distribution was present across the basin.

4 The PNA and El Niño The Pacific North American (PNA) Index is a climate index that describes one of the most prominent modes of low-frequency variability in the Northern Hemisphere extratropics. The positive phase of the PNA is characterized by a stronger than normal Aleutian low, and a stronger high pressure system over the western US (Figure 7). The negative phase of the PNA is characterized by weaker than normal lows across the Aleutians/Central Pacific, but a stronger trough across the western United States. The PNA is a natural mode of climate variability, but it tends to very strongly with ENSO events the positive phase of the PNA is strongly correlated to El Niño events, while the negative phase is strongly correlated to La Niña events. (Climate Prediction Center: The period of September-November 2009 showed an average PNA value of The average sea level pressure anomaly for the period 1 September 7 December (Figure 8) is in line with the characteristics of a positive PNA, with a deep anomaly over the Aleutian Islands and Gulf of Alaska. Eight of the ten storms that were observed to have central pressures of less than 970mb occurred when the PNA Index was in a positive phase (Figure 9), meaning that the Aleutian Low, and the main low track was enhanced. Conclusion The presence of several recurving tropical systems over the western Pacific affected the weather pattern during the transition season in two ways. Firstly, warm, humid tropical air was carried into the mid-latitudes as these systems tracked northeastward and merged with the main low track. Secondly, several strong recurving typhoons served to push warmer tropical waters northward into the mid-latitudes, causing a warm SST anomaly to develop across the western Pacific. This allowed low pressure systems that developed off the coast of Japan to remain over warmer waters for longer; when those lows then interacted with cold air at higher latitudes, the resulting dynamics allowed lows to deepen further, and often more rapidly, than typically is expected. Similarly, the effects of El Niño on the general weather pattern of the North Pacific, and El Niño s interaction with the Pacific/North American pattern resulted in an enhanced Aleutian low pressure system across the central Pacific and Gulf of Alaska, resulting in a more active main low track across the basin. The enhanced main low track served to allow stronger low pressure systems to develop (in concert with the observed SST anomaly), which caused the several violent storms that were observed over the course of this transition season.

5 Figure 1. Ninety-day average wave heights (m) and storm tracks for the period 11 September 09 December. Courtesy Climate Prediction Center :

6 Figure 2. Time series of area averaged sea surface temperature anomalies in the Niño regions [Niño-1+2 (0-10S, 90W-80W), Niño-3 (5N-5S, 150W-90W), Niño-3.4 (5N-5S, 170W-120W), Niño-4 (5N-5S, 150W-160E)]. SST anomalies are departures from the base period weekly means. (Xue et. al., 2003, J. Climate, 16, ). Graphics courtesy Climate Prediction Center.

7 Figure 3. Typical Sea surface temperature anomaly distributions associated the warm (El Niño) phase and cool (La Niña) phase of the ENSO Cycle. Graphic courtesy National Oceanic and Atmospheric Administration.

8 Figure 4. Typical winter weather patters during El Niño and La Niña events. Courtesy Climate Prediction Center (

9 Month 2009 Average September October 5 (plus 1 TD) 4.7 November 3 (plus 2 TDs) 2.9 December** 0 (Plus 1 TD) 1.6 Table 1. Number of tropical systems of tropical storm strength and higher in the West Pacific. This list does not include Tropical Depressions (TD). However, there have been a total of 4 TDs in the NW Pacific in Oct., Nov., and Dec. 2009, many of which have brought tropical moisture into the mid-latitudes.** As of Dec-07, 2009 Figure 5. Mean position for tropical depression formation across the western Pacific for Strong La Niña, La Niña, ENSO Neutral, El Niño and strong El Niño events. Chart produced by the WNI-Voyage Planning team.

10 Figure 6. Average sea surface temperature anomaly (degrees C) for the period September 1 December 7, as compared to climatogical mean From NCAR/NCEP global Reanalysis Data provided by Earth System Research Laboratory. Figure 7. Empirical Orthogonal Function loading pattern for sea level pressure anomalies associated with the positive phase of the Pacific/North American Index. Courtesy Joint Institute for the study of Atmosphere and Ocean.

11 Figure 8. Composite mean Sea Level Pressure anomaly for the period September 1 December 7, as compared to climatogical mean From NCAR/NCEP global Reanalysis Data provided by Earth System Research Laboratory. Figure 9. Observed daily PNA Index value. Vertical lines indicate the approximate date of storms that were observed to have central pressures of less than 970mb. Pink Lines indicate Positive PNA value at the time of observation and green lines indicate Negative PNA value at the time of observation. PNA index figure courtesy Climate Prediction Center (

North Pacific Climate Overview N. Bond (UW/JISAO), J. Overland (NOAA/PMEL) Contact: Last updated: August 2009

North Pacific Climate Overview N. Bond (UW/JISAO), J. Overland (NOAA/PMEL) Contact: Last updated: August 2009 North Pacific Climate Overview N. Bond (UW/JISAO), J. Overland (NOAA/PMEL) Contact: Nicholas.Bond@noaa.gov Last updated: August 2009 Summary. The North Pacific atmosphere-ocean system from fall 2008 through

More information

2013 ATLANTIC HURRICANE SEASON OUTLOOK. June RMS Cat Response

2013 ATLANTIC HURRICANE SEASON OUTLOOK. June RMS Cat Response 2013 ATLANTIC HURRICANE SEASON OUTLOOK June 2013 - RMS Cat Response Season Outlook At the start of the 2013 Atlantic hurricane season, which officially runs from June 1 to November 30, seasonal forecasts

More information

Percentage of normal rainfall for August 2017 Departure from average air temperature for August 2017

Percentage of normal rainfall for August 2017 Departure from average air temperature for August 2017 New Zealand Climate Update No 219, August 2017 Current climate August 2017 Overall, mean sea level pressure was lower than normal over and to the west of New Zealand during August while higher than normal

More information

7 December 2016 Tokyo Climate Center, Japan Meteorological Agency

7 December 2016 Tokyo Climate Center, Japan Meteorological Agency Summary of the 2016 Asian Summer Monsoon 7 December 2016 Tokyo Climate Center, Japan Meteorological Agency This report summarizes the characteristics of the surface climate and atmospheric/oceanographic

More information

ATMOSPHERIC MODELLING. GEOG/ENST 3331 Lecture 9 Ahrens: Chapter 13; A&B: Chapters 12 and 13

ATMOSPHERIC MODELLING. GEOG/ENST 3331 Lecture 9 Ahrens: Chapter 13; A&B: Chapters 12 and 13 ATMOSPHERIC MODELLING GEOG/ENST 3331 Lecture 9 Ahrens: Chapter 13; A&B: Chapters 12 and 13 Agenda for February 3 Assignment 3: Due on Friday Lecture Outline Numerical modelling Long-range forecasts Oscillations

More information

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (December 2017)

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (December 2017) UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (December 2017) 1. Review of Regional Weather Conditions for November 2017 1.1 In November 2017, Southeast Asia experienced inter-monsoon conditions in the first

More information

Wind: Global Systems Chapter 10

Wind: Global Systems Chapter 10 Wind: Global Systems Chapter 10 General Circulation of the Atmosphere General circulation of the atmosphere describes average wind patterns and is useful for understanding climate Over the earth, incoming

More information

North Pacific Climate Overview N. Bond (UW/JISAO), J. Overland (NOAA/PMEL) Contact: Last updated: September 2008

North Pacific Climate Overview N. Bond (UW/JISAO), J. Overland (NOAA/PMEL) Contact: Last updated: September 2008 North Pacific Climate Overview N. Bond (UW/JISAO), J. Overland (NOAA/PMEL) Contact: Nicholas.Bond@noaa.gov Last updated: September 2008 Summary. The North Pacific atmosphere-ocean system from fall 2007

More information

Hurricanes. April 14, 2009

Hurricanes. April 14, 2009 Tropical Weather & Hurricanes Chapter 15 April 14, 2009 Tropical meteorology Tropics characterized by seasonal wet and drier periods- wet when sun is nearly overhead at noon and inter-tropical convergence

More information

Weathernews Looks Back at 2015: A Year of Storms. Powerful Typhoons Occurred with Changing Patterns in El Niño Years

Weathernews Looks Back at 2015: A Year of Storms. Powerful Typhoons Occurred with Changing Patterns in El Niño Years NEWS RELEASE January 27th, 2016 Weathernews Looks Back at 2015: A Year of Storms Powerful Typhoons Occurred with Changing Patterns in El Niño Years Weathernews Inc. (Chiba, Japan; Chihito Kusabiraki/CEO)

More information

New Zealand Climate Update No 223, January 2018 Current climate December 2017

New Zealand Climate Update No 223, January 2018 Current climate December 2017 New Zealand Climate Update No 223, January 2018 Current climate December 2017 December 2017 was characterised by higher than normal sea level pressure over New Zealand and the surrounding seas. This pressure

More information

ALASKA REGION CLIMATE FORECAST BRIEFING. October 27, 2017 Rick Thoman National Weather Service Alaska Region

ALASKA REGION CLIMATE FORECAST BRIEFING. October 27, 2017 Rick Thoman National Weather Service Alaska Region ALASKA REGION CLIMATE FORECAST BRIEFING October 27, 2017 Rick Thoman National Weather Service Alaska Region Today Feature of the month: West Pacific Typhoons Climate Forecast Basics Climate System Review

More information

Verification of the Seasonal Forecast for the 2005/06 Winter

Verification of the Seasonal Forecast for the 2005/06 Winter Verification of the Seasonal Forecast for the 2005/06 Winter Shingo Yamada Tokyo Climate Center Japan Meteorological Agency 2006/11/02 7 th Joint Meeting on EAWM Contents 1. Verification of the Seasonal

More information

Mid-season Storm Surge Update: December, 2013

Mid-season Storm Surge Update: December, 2013 December 17, 2012 Ambleside Beach (Photograph by: Mark van Manen, PNG) Mid-season Storm Surge Update: December, 2013 Mid-season discussion of tidal and climate conditions affecting extreme water levels

More information

What a Hurricane Needs to Develop

What a Hurricane Needs to Develop Massive Storms! Hurricanes What a Hurricane Needs to Develop Warm tropical water - at least 80 F High Humidity Light wind Low Pressure Area Form between 5 and 20 latitude Hurricane Ingredients Hurricane

More information

Weather and Climate Summary and Forecast March 2018 Report

Weather and Climate Summary and Forecast March 2018 Report Weather and Climate Summary and Forecast March 2018 Report Gregory V. Jones Linfield College March 7, 2018 Summary: The ridge pattern that brought drier and warmer conditions from December through most

More information

4/29/2011. Mid-latitude cyclones form along a

4/29/2011. Mid-latitude cyclones form along a Chapter 10: Cyclones: East of the Rocky Mountain Extratropical Cyclones Environment prior to the development of the Cyclone Initial Development of the Extratropical Cyclone Early Weather Along the Fronts

More information

What a Hurricane Needs to Develop

What a Hurricane Needs to Develop Weather Weather is the current atmospheric conditions, such as air temperature, wind speed, wind direction, cloud cover, precipitation, relative humidity, air pressure, etc. 8.10B: global patterns of atmospheric

More information

Early May Cut-off low and Mid-Atlantic rains

Early May Cut-off low and Mid-Atlantic rains Abstract: Early May Cut-off low and Mid-Atlantic rains By Richard H. Grumm National Weather Service State College, PA A deep 500 hpa cutoff developed in the southern Plains on 3 May 2013. It produced a

More information

New Zealand Climate Update No 226, April 2018 Current climate March 2018

New Zealand Climate Update No 226, April 2018 Current climate March 2018 New Zealand Climate Update No 226, April 2018 Current climate March 2018 March 2018 was characterised by significantly higher pressure than normal to the east of New Zealand. This pressure pattern, in

More information

Global Climate Patterns and Their Impacts on North American Weather

Global Climate Patterns and Their Impacts on North American Weather Global Climate Patterns and Their Impacts on North American Weather By Julie Malmberg and Jessica Lowrey, Western Water Assessment Introduction This article provides a broad overview of various climate

More information

Winter Forecast. Allan Huffman RaleighWx

Winter Forecast. Allan Huffman RaleighWx Winter 2015-16 Forecast Allan Huffman RaleighWx Disclaimer Seasonal forecasting is difficult and you are always learning. I attempt to look at all factors I understand and have seen correlate in the past

More information

THE INFLUENCE OF CLIMATE TELECONNECTIONS ON WINTER TEMPERATURES IN WESTERN NEW YORK INTRODUCTION

THE INFLUENCE OF CLIMATE TELECONNECTIONS ON WINTER TEMPERATURES IN WESTERN NEW YORK INTRODUCTION Middle States Geographer, 2014, 47: 60-67 THE INFLUENCE OF CLIMATE TELECONNECTIONS ON WINTER TEMPERATURES IN WESTERN NEW YORK Frederick J. Bloom and Stephen J. Vermette Department of Geography and Planning

More information

Introduction of climate monitoring and analysis products for one-month forecast

Introduction of climate monitoring and analysis products for one-month forecast Introduction of climate monitoring and analysis products for one-month forecast TCC Training Seminar on One-month Forecast on 13 November 2018 10:30 11:00 1 Typical flow of making one-month forecast Observed

More information

The feature of atmospheric circulation in the extremely warm winter 2006/2007

The feature of atmospheric circulation in the extremely warm winter 2006/2007 The feature of atmospheric circulation in the extremely warm winter 2006/2007 Hiroshi Hasegawa 1, Yayoi Harada 1, Hiroshi Nakamigawa 1, Atsushi Goto 1 1 Climate Prediction Division, Japan Meteorological

More information

KUALA LUMPUR MONSOON ACTIVITY CENT

KUALA LUMPUR MONSOON ACTIVITY CENT T KUALA LUMPUR MONSOON ACTIVITY CENT 2 ALAYSIAN METEOROLOGICAL http://www.met.gov.my DEPARTMENT MINISTRY OF SCIENCE. TECHNOLOGY AND INNOVATIO Introduction Atmospheric and oceanic conditions over the tropical

More information

Weather and Climate Summary and Forecast December 2017 Report

Weather and Climate Summary and Forecast December 2017 Report Weather and Climate Summary and Forecast December 2017 Report Gregory V. Jones Linfield College December 5, 2017 Summary: November was relatively cool and wet from central California throughout most of

More information

Percentage of normal rainfall for April 2018 Departure from average air temperature for April 2018

Percentage of normal rainfall for April 2018 Departure from average air temperature for April 2018 New Zealand Climate Update No 227, May 2018 Current climate April 2018 Overall, April 2018 was characterised by lower pressure than normal over and to the southeast of New Zealand. Unlike the first three

More information

Pacific Decadal Oscillation ( PDO ):

Pacific Decadal Oscillation ( PDO ): Time again for my annual Winter Weather Outlook. Here's just a small part of the items I considered this year and how I think they will play out with our winter of 2015-2016. El Nino / La Nina: When looking

More information

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (February 2018)

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (February 2018) UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (February 2018) 1. Review of Regional Weather Conditions for January 2018 1.1 The prevailing Northeast monsoon conditions over Southeast Asia strengthened in January

More information

Here s what a weak El Nino usually brings to the nation with temperatures:

Here s what a weak El Nino usually brings to the nation with temperatures: Time again for my annual Winter Weather Outlook. Here's just a small part of the items I considered this year and how I think they will play out with our winter of 2018-2019. El Nino / La Nina: When looking

More information

Name: Date: Hour: Comparing the Effects of El Nino & La Nina on the Midwest (E4.2c)

Name: Date: Hour: Comparing the Effects of El Nino & La Nina on the Midwest (E4.2c) Purpose: Comparing the Effects of El Nino & La Nina on the Midwest (E4.2c) To compare the effects of El Nino and La Nina on the Midwest United States. Background Knowledge: The El Nino-Southern Oscillation

More information

Satellites, Weather and Climate Module??: Polar Vortex

Satellites, Weather and Climate Module??: Polar Vortex Satellites, Weather and Climate Module??: Polar Vortex SWAC Jan 2014 AKA Circumpolar Vortex Science or Hype? Will there be one this year? Today s objectives Pre and Post exams What is the Polar Vortex

More information

PRMS WHITE PAPER 2014 NORTH ATLANTIC HURRICANE SEASON OUTLOOK. June RMS Event Response

PRMS WHITE PAPER 2014 NORTH ATLANTIC HURRICANE SEASON OUTLOOK. June RMS Event Response PRMS WHITE PAPER 2014 NORTH ATLANTIC HURRICANE SEASON OUTLOOK June 2014 - RMS Event Response 2014 SEASON OUTLOOK The 2013 North Atlantic hurricane season saw the fewest hurricanes in the Atlantic Basin

More information

WINTER FORECAST NY Metro

WINTER FORECAST NY Metro 2015-2016 WINTER FORECAST NY Metro Weather @NY_WX DISCLAIMER: Seasonal forecasting is difficult and this is my first attempt at a Winter Forecast. I ve looked at all factors and put them together to create

More information

National Wildland Significant Fire Potential Outlook

National Wildland Significant Fire Potential Outlook National Wildland Significant Fire Potential Outlook National Interagency Fire Center Predictive Services Issued: September, 2007 Wildland Fire Outlook September through December 2007 Significant fire

More information

Weather and Climate Summary and Forecast January 2018 Report

Weather and Climate Summary and Forecast January 2018 Report Weather and Climate Summary and Forecast January 2018 Report Gregory V. Jones Linfield College January 5, 2018 Summary: A persistent ridge of high pressure over the west in December produced strong inversions

More information

Thai Meteorological Department, Ministry of Digital Economy and Society

Thai Meteorological Department, Ministry of Digital Economy and Society Thai Meteorological Department, Ministry of Digital Economy and Society Three-month Climate Outlook For November 2017 January 2018 Issued on 31 October 2017 -----------------------------------------------------------------------------------------------------------------------------

More information

Winter Forecast. Allan Huffman RaleighWx

Winter Forecast. Allan Huffman RaleighWx Winter 2014-15 Forecast Allan Huffman RaleighWx Winter 2014-15 Combination of weak/moderate El Nino/+PDO/-QBO and well above average snow cover and snow cover increase this Fall in Siberia point to a winter

More information

Lecture 5: Atmospheric General Circulation and Climate

Lecture 5: Atmospheric General Circulation and Climate Lecture 5: Atmospheric General Circulation and Climate Geostrophic balance Zonal-mean circulation Transients and eddies Meridional energy transport Moist static energy Angular momentum balance Atmosphere

More information

South & South East Asian Region:

South & South East Asian Region: Issued: 15 th December 2017 Valid Period: January June 2018 South & South East Asian Region: Indonesia Tobacco Regions 1 A] Current conditions: 1] El Niño-Southern Oscillation (ENSO) ENSO Alert System

More information

Weather and Climate Summary and Forecast February 2018 Report

Weather and Climate Summary and Forecast February 2018 Report Weather and Climate Summary and Forecast February 2018 Report Gregory V. Jones Linfield College February 5, 2018 Summary: For the majority of the month of January the persistent ridge of high pressure

More information

Weather and Climate Summary and Forecast October 2018 Report

Weather and Climate Summary and Forecast October 2018 Report Weather and Climate Summary and Forecast October 2018 Report Gregory V. Jones Linfield College October 4, 2018 Summary: Much of Washington, Oregon, coastal California and the Bay Area and delta region

More information

El Niño: How it works, how we observe it. William Kessler and the TAO group NOAA / Pacific Marine Environmental Laboratory

El Niño: How it works, how we observe it. William Kessler and the TAO group NOAA / Pacific Marine Environmental Laboratory El Niño: How it works, how we observe it William Kessler and the TAO group NOAA / Pacific Marine Environmental Laboratory The normal situation in the tropical Pacific: a coupled ocean-atmosphere system

More information

Please be ready for today by:

Please be ready for today by: Please be ready for today by: 1. HW out for a stamp 2. Paper and pencil/pen for notes 3. Be ready to discuss what you know about El Nino after you view the video clip What is El Nino? El Nino Basics El

More information

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 11 November 2013

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 11 November 2013 ENSO Cycle: Recent Evolution, Current Status and Predictions Update prepared by Climate Prediction Center / NCEP 11 November 2013 Outline Overview Recent Evolution and Current Conditions Oceanic Niño Index

More information

Global Atmospheric Circulation

Global Atmospheric Circulation Global Atmospheric Circulation Polar Climatology & Climate Variability Lecture 11 Nov. 22, 2010 Global Atmospheric Circulation Global Atmospheric Circulation Global Atmospheric Circulation The Polar Vortex

More information

Weather and Climate Summary and Forecast April 2018 Report

Weather and Climate Summary and Forecast April 2018 Report Weather and Climate Summary and Forecast April 2018 Report Gregory V. Jones Linfield College April 4, 2018 Summary: A near Miracle March played out bringing cooler and wetter conditions to the majority

More information

Winter Steve Todd Meteorologist In Charge National Weather Service Portland, OR

Winter Steve Todd Meteorologist In Charge National Weather Service Portland, OR Winter 07-08 Steve Todd Meteorologist In Charge National Weather Service Portland, OR Overview Winter Weather Outlook How to stay informed Winter Outlook LaNina conditions are present across the tropical

More information

Weather Outlook for Spring and Summer in Central TX. Aaron Treadway Meteorologist National Weather Service Austin/San Antonio

Weather Outlook for Spring and Summer in Central TX. Aaron Treadway Meteorologist National Weather Service Austin/San Antonio Weather Outlook for Spring and Summer in Central TX Aaron Treadway Meteorologist National Weather Service Austin/San Antonio Outline A Look Back At 2014 Spring 2015 So Far El Niño Update Climate Prediction

More information

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (September 2017)

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (September 2017) UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (September 2017) 1. Review of Regional Weather Conditions in August 2017 1.1 Southwest Monsoon conditions continued to prevail in the region in August 2017. The

More information

Introduction of products for Climate System Monitoring

Introduction of products for Climate System Monitoring Introduction of products for Climate System Monitoring 1 Typical flow of making one month forecast Textbook P.66 Observed data Atmospheric and Oceanic conditions Analysis Numerical model Ensemble forecast

More information

Weather and Climate Summary and Forecast October 2017 Report

Weather and Climate Summary and Forecast October 2017 Report Weather and Climate Summary and Forecast October 2017 Report Gregory V. Jones Linfield College October 4, 2017 Summary: Typical variability in September temperatures with the onset of fall conditions evident

More information

1. Introduction. 2. Verification of the 2010 forecasts. Research Brief 2011/ February 2011

1. Introduction. 2. Verification of the 2010 forecasts. Research Brief 2011/ February 2011 Research Brief 2011/01 Verification of Forecasts of Tropical Cyclone Activity over the Western North Pacific and Number of Tropical Cyclones Making Landfall in South China and the Korea and Japan region

More information

Northwest Outlook October 2016

Northwest Outlook October 2016 Northwest Outlook October 2016 Rainfall Opportunities and Challenges Rainfall over the month of September presented some challenges for the fall harvest while other producers benefitted. Figure 1a shows

More information

ALASKA REGION CLIMATE OUTLOOK BRIEFING. December 22, 2017 Rick Thoman National Weather Service Alaska Region

ALASKA REGION CLIMATE OUTLOOK BRIEFING. December 22, 2017 Rick Thoman National Weather Service Alaska Region ALASKA REGION CLIMATE OUTLOOK BRIEFING December 22, 2017 Rick Thoman National Weather Service Alaska Region Today s Outline Feature of the month: Autumn sea ice near Alaska Climate Forecast Basics Climate

More information

Weather and Climate Summary and Forecast August 2018 Report

Weather and Climate Summary and Forecast August 2018 Report Weather and Climate Summary and Forecast August 2018 Report Gregory V. Jones Linfield College August 5, 2018 Summary: July 2018 will likely go down as one of the top five warmest July s on record for many

More information

Global Weather Trade Winds etc.notebook February 17, 2017

Global Weather Trade Winds etc.notebook February 17, 2017 Global Weather 1 north pole northern hemisphere equator southern hemisphere south pole 2 We have seasons because of the Earth's tilt The seasons are opposite in the northern and southern hemispheres winter

More information

MAURITIUS METEOROLOGICAL SERVICES

MAURITIUS METEOROLOGICAL SERVICES MAURITIUS METEOROLOGICAL SERVICES CLIMATE SEPTEMBER 2018 Introduction Synoptic weather pattern over the region portrayed September as a transition month. The month started with wintry characteristics.

More information

ENSO: Recent Evolution, Current Status and Predictions. Update prepared by: Climate Prediction Center / NCEP 9 November 2015

ENSO: Recent Evolution, Current Status and Predictions. Update prepared by: Climate Prediction Center / NCEP 9 November 2015 ENSO: Recent Evolution, Current Status and Predictions Update prepared by: Climate Prediction Center / NCEP 9 November 2015 Outline Summary Recent Evolution and Current Conditions Oceanic Niño Index (ONI)

More information

El Niño / Southern Oscillation

El Niño / Southern Oscillation El Niño / Southern Oscillation Student Packet 2 Use contents of this packet as you feel appropriate. You are free to copy and use any of the material in this lesson plan. Packet Contents Introduction on

More information

California 120 Day Precipitation Outlook Issued Tom Dunklee Global Climate Center

California 120 Day Precipitation Outlook Issued Tom Dunklee Global Climate Center California 120 Day Precipitation Outlook Issued 11-01-2008 Tom Dunklee Global Climate Center This is my second updated outlook for precipitation patterns and amounts for the next 4 s of the current rainy

More information

Chapter 24 Tropical Cyclones

Chapter 24 Tropical Cyclones Chapter 24 Tropical Cyclones Tropical Weather Systems Tropical disturbance a cluster of thunderstorms about 250 to 600 km in diameter, originating in the tropics or sub-tropics Tropical depression a cluster

More information

ENSO UPDATE By Joseph D Aleo, CCM

ENSO UPDATE By Joseph D Aleo, CCM ENSO UPDATE By Joseph D Aleo, CCM El Nino is still hanging on but likely not for very long. Warmer than normal water can still be seen along the equator in the tropical Pacific. It is even warmer in the

More information

Winds and Global Circulation

Winds and Global Circulation Winds and Global Circulation Atmospheric Pressure Winds Global Wind and Pressure Patterns Oceans and Ocean Currents El Nino How is Energy Transported to its escape zones? Both atmospheric and ocean transport

More information

New Zealand Climate Update No 221, October 2017 Current climate October 2017

New Zealand Climate Update No 221, October 2017 Current climate October 2017 New Zealand Climate Update No 221, October 2017 Current climate October 2017 October 2017 was characterised by higher than normal sea level pressure over New Zealand and the surrounding seas. This consistent

More information

ESCI 241 Meteorology Lesson 19 Tropical Cyclones Dr. DeCaria

ESCI 241 Meteorology Lesson 19 Tropical Cyclones Dr. DeCaria ESCI 241 Meteorology Lesson 19 Tropical Cyclones Dr. DeCaria READING: Chapter 16 GENERAL A tropical cyclone is a large, low-pressure system that forms over the tropical oceans. Tropical cyclones are classified

More information

August Forecast Update for Atlantic Hurricane Activity in 2012

August Forecast Update for Atlantic Hurricane Activity in 2012 August Forecast Update for Atlantic Hurricane Activity in 2012 Issued: 6 th August 2012 by Professor Mark Saunders and Dr Adam Lea Dept. of Space and Climate Physics, UCL (University College London), UK

More information

Climate Outlook through 2100 South Florida Ecological Services Office Vero Beach, FL September 9, 2014

Climate Outlook through 2100 South Florida Ecological Services Office Vero Beach, FL September 9, 2014 Climate Outlook through 2100 South Florida Ecological Services Office Vero Beach, FL September 9, 2014 Short Term Drought Map: Short-term (

More information

Weather and Climate Summary and Forecast Winter

Weather and Climate Summary and Forecast Winter Weather and Climate Summary and Forecast Winter 2016-17 Gregory V. Jones Southern Oregon University December 5, 2016 Well after an October that felt more like November, we just finished a November that

More information

Winter. Here s what a weak La Nina usually brings to the nation with tempseraures:

Winter. Here s what a weak La Nina usually brings to the nation with tempseraures: 2017-2018 Winter Time again for my annual Winter Weather Outlook. Here's just a small part of the items I considered this year and how I think they will play out with our winter of 2017-2018. El Nino /

More information

Hurricanes Part I Structure and Climatology by Professor Steven Businger. Hurricane Katrina

Hurricanes Part I Structure and Climatology by Professor Steven Businger. Hurricane Katrina Hurricanes Part I Structure and Climatology by Professor Steven Businger Hurricane Katrina Hurricanes Part I Structure and Climatology by Professor Steven Businger What is a hurricane? What is the structure

More information

The 2009 Hurricane Season Overview

The 2009 Hurricane Season Overview The 2009 Hurricane Season Overview Jae-Kyung Schemm Gerry Bell Climate Prediction Center NOAA/ NWS/ NCEP 1 Overview outline 1. Current status for the Atlantic, Eastern Pacific and Western Pacific basins

More information

Unseasonable weather conditions in Japan in August 2014

Unseasonable weather conditions in Japan in August 2014 Unseasonable weather conditions in Japan in August 2014 Summary of analysis by the TCC Advisory Panel on Extreme Climatic Events In an extraordinary session held at the Japan Meteorological Agency on 3

More information

Ocean in Motion 7: El Nino and Hurricanes!

Ocean in Motion 7: El Nino and Hurricanes! Ocean in Motion 7: El Nino and Hurricanes! A. Overview 1. Ocean in Motion -- El Nino and hurricanes We will look at the ocean-atmosphere interactions that cause El Nino and hurricanes. Using vocabulary

More information

Weather and Climate Summary and Forecast Fall/Winter 2016

Weather and Climate Summary and Forecast Fall/Winter 2016 Weather and Climate Summary and Forecast Fall/Winter 2016 Gregory V. Jones Southern Oregon University November 5, 2016 After a year where we were seemingly off by a month in terms of temperatures (March

More information

Massive Storms! 8.10C Identify the role of the oceans in the formation of weather systems such as hurricanes

Massive Storms! 8.10C Identify the role of the oceans in the formation of weather systems such as hurricanes Massive Storms! 8.10C Identify the role of the oceans in the formation of weather systems such as hurricanes Instructional page: Each person in group will take on one portion or set of questions: Each

More information

Fire Weather Drivers, Seasonal Outlook and Climate Change. Steven McGibbony, Severe Weather Manager Victoria Region Friday 9 October 2015

Fire Weather Drivers, Seasonal Outlook and Climate Change. Steven McGibbony, Severe Weather Manager Victoria Region Friday 9 October 2015 Fire Weather Drivers, Seasonal Outlook and Climate Change Steven McGibbony, Severe Weather Manager Victoria Region Friday 9 October 2015 Outline Weather and Fire Risk Environmental conditions leading to

More information

ENSO, AO, and climate in Japan. 15 November 2016 Yoshinori Oikawa, Tokyo Climate Center, Japan Meteorological Agency

ENSO, AO, and climate in Japan. 15 November 2016 Yoshinori Oikawa, Tokyo Climate Center, Japan Meteorological Agency ENSO, AO, and climate in Japan 15 November 2016 Yoshinori Oikawa, Tokyo Climate Center, Japan Meteorological Agency Aims of this lecture At the end of the yesterday s lecture, Hare-run said, - In the exercise

More information

Weather and Climate Summary and Forecast Summer 2017

Weather and Climate Summary and Forecast Summer 2017 Weather and Climate Summary and Forecast Summer 2017 Gregory V. Jones Southern Oregon University August 4, 2017 July largely held true to forecast, although it ended with the start of one of the most extreme

More information

b. The boundary between two different air masses is called a.

b. The boundary between two different air masses is called a. NAME Earth Science Weather WebQuest Part 1. Air Masses 1. Find out what an air mass is. http://okfirst.mesonet.org/train/meteorology/airmasses.html a. What is an air mass? An air mass is b. The boundary

More information

Ocean cycles and climate ENSO, PDO, AMO, AO

Ocean cycles and climate ENSO, PDO, AMO, AO Ocean cycles and climate ENSO, PDO, AMO, AO 3 2.5 2 enso-index 1.5 1 0.5 0-0.5-1 enso 3.4 -index - 1996 to 1999-1.5 1996 1997 1998 1999 Bob Tisdale Bob Tisdale Bob Tisdale ENSO mechanisms animation http://esminfo.prenhall.com/science/geoanimations/animations/26_ninonina.html

More information

MPACT OF EL-NINO ON SUMMER MONSOON RAINFALL OF PAKISTAN

MPACT OF EL-NINO ON SUMMER MONSOON RAINFALL OF PAKISTAN MPACT OF EL-NINO ON SUMMER MONSOON RAINFALL OF PAKISTAN Abdul Rashid 1 Abstract: El-Nino is the dominant mod of inter- annual climate variability on a planetary scale. Its impact is associated worldwide

More information

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 23 April 2012

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 23 April 2012 ENSO Cycle: Recent Evolution, Current Status and Predictions Update prepared by Climate Prediction Center / NCEP 23 April 2012 Outline Overview Recent Evolution and Current Conditions Oceanic Niño Index

More information

Introduction to Meteorology & Climate. Climate & Earth System Science. Atmosphere Ocean Interactions. A: Structure of the Ocean.

Introduction to Meteorology & Climate. Climate & Earth System Science. Atmosphere Ocean Interactions. A: Structure of the Ocean. Climate & Earth System Science Introduction to Meteorology & Climate MAPH 10050 Peter Lynch Peter Lynch Meteorology & Climate Centre School of Mathematical Sciences University College Dublin Meteorology

More information

Weather and Climate Summary and Forecast March 2019 Report

Weather and Climate Summary and Forecast March 2019 Report Weather and Climate Summary and Forecast March 2019 Report Gregory V. Jones Linfield College March 2, 2019 Summary: Dramatic flip from a mild winter to a top five coldest February on record in many locations

More information

Ocean-Atmosphere Interactions and El Niño Lisa Goddard

Ocean-Atmosphere Interactions and El Niño Lisa Goddard Ocean-Atmosphere Interactions and El Niño Lisa Goddard Advanced Training Institute on Climatic Variability and Food Security 2002 July 9, 2002 Coupled Behavior in tropical Pacific SST Winds Upper Ocean

More information

How Patterns Far Away Can Influence Our Weather. Mark Shafer University of Oklahoma Norman, OK

How Patterns Far Away Can Influence Our Weather. Mark Shafer University of Oklahoma Norman, OK Teleconnections How Patterns Far Away Can Influence Our Weather Mark Shafer University of Oklahoma Norman, OK Teleconnections Connectedness of large-scale weather patterns across the world If you poke

More information

At the Midpoint of the 2008

At the Midpoint of the 2008 At the Midpoint of the 2008 Atlantic Hurricane Season Editor s note: It has been an anxious couple of weeks for those with financial interests in either on- or offshore assets in the Gulf of Mexico and

More information

Lecture 8: Natural Climate Variability

Lecture 8: Natural Climate Variability Lecture 8: Natural Climate Variability Extratropics: PNA, NAO, AM (aka. AO), SAM Tropics: MJO Coupled A-O Variability: ENSO Decadal Variability: PDO, AMO Unforced vs. Forced Variability We often distinguish

More information

Weather Outlook: 2015 Growing Season

Weather Outlook: 2015 Growing Season Weather Outlook: 2015 Growing Season Leon F. Osborne Chester Fritz Distinguished Professor Regional Weather Information Center University of North Dakota Grand Forks, North Dakota Why Should We Be Concerned?

More information

New Zealand Climate Update No 222, November 2017 Current climate November 2017

New Zealand Climate Update No 222, November 2017 Current climate November 2017 New Zealand Climate Update No 222, November 2017 Current climate November 2017 November 2017 was characterised by higher than normal sea level pressure over New Zealand and the surrounding seas, particularly

More information

ENSO: Recent Evolution, Current Status and Predictions. Update prepared by: Climate Prediction Center / NCEP 30 October 2017

ENSO: Recent Evolution, Current Status and Predictions. Update prepared by: Climate Prediction Center / NCEP 30 October 2017 ENSO: Recent Evolution, Current Status and Predictions Update prepared by: Climate Prediction Center / NCEP 30 October 2017 Outline Summary Recent Evolution and Current Conditions Oceanic Niño Index (ONI)

More information

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 15 July 2013

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 15 July 2013 ENSO Cycle: Recent Evolution, Current Status and Predictions Update prepared by Climate Prediction Center / NCEP 15 July 2013 Outline Overview Recent Evolution and Current Conditions Oceanic Niño Index

More information

AnuMS 2018 Atlantic Hurricane Season Forecast

AnuMS 2018 Atlantic Hurricane Season Forecast AnuMS 2018 Atlantic Hurricane Season Forecast Issued: May 10, 2018 by Dale C. S. Destin (follow @anumetservice) Director (Ag), Antigua and Barbuda Meteorological Service (ABMS) The *AnuMS (Antigua Met

More information

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 24 September 2012

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 24 September 2012 ENSO Cycle: Recent Evolution, Current Status and Predictions Update prepared by Climate Prediction Center / NCEP 24 September 2012 Outline Overview Recent Evolution and Current Conditions Oceanic Niño

More information

AnuMS 2018 Atlantic Hurricane Season Forecast

AnuMS 2018 Atlantic Hurricane Season Forecast AnuMS 2018 Atlantic Hurricane Season Forecast : June 11, 2018 by Dale C. S. Destin (follow @anumetservice) Director (Ag), Antigua and Barbuda Meteorological Service (ABMS) The *AnuMS (Antigua Met Service)

More information

An upper to mid level circulation (Low) in the NW Caribbean is

An upper to mid level circulation (Low) in the NW Caribbean is WEEKLY WEATHER OUTLOOK BELIZE, CENTRAL AMERICA PERIOD: Monday-Monday, Oct. 1 October 8, 2012 DATE ISSUED: Monday, Oct 1, 2012 6:00 am RFrutos EcoSolutions & Services SYNOPSIS: An upper to mid level circulation

More information

SUMMARY OF THE 2011 TYPHOON SEASON

SUMMARY OF THE 2011 TYPHOON SEASON ECONOMIC AND SOCIAL COMMISSION FOR ASIA AND THE PACIFIC AND WORLD METEOROLOGICAL ORGANIZATION WRD/TC.44/4.1 Add. 2 06 February 2012 Typhoon Committee Forty Fourth Session 06 to 12 February 2012 Hangzhou,

More information

El Niño Update Impacts on Florida

El Niño Update Impacts on Florida Current Issues in Emergency Management (CIEM) Sessions 1 &2 October 12 th and 26 th, 2006 Florida Division of Emergency Management Tallahassee, Florida El Niño Update Impacts on Florida Bart Hagemeyer

More information